diff --git a/CHANGELOG.md b/CHANGELOG.md
index 58265768f..1de2f6d38 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@
     * Fixed `Flex Pages` with `00.home` page not having ordering set
     * Fixed `Flex Pages` not updating empty content on save [#2890](https://github.com/getgrav/grav/issues/2890)
     * Fixed creating new Flex User with file storage
+    * Fixed saving new `Flex Object` with custom key
 
 # v1.7.0-rc.8
 ## 03/19/2020
diff --git a/system/src/Grav/Common/Flex/Types/Users/UserIndex.php b/system/src/Grav/Common/Flex/Types/Users/UserIndex.php
index a0ff57ba9..e65bad79e 100644
--- a/system/src/Grav/Common/Flex/Types/Users/UserIndex.php
+++ b/system/src/Grav/Common/Flex/Types/Users/UserIndex.php
@@ -118,15 +118,15 @@ class UserIndex extends FlexIndex
     }
 
     /**
-     * @param array $entry
+     * @param array $meta
      * @param array $data
      */
-    protected static function updateIndexData(array &$entry, array $data)
+    public static function updateObjectMeta(array &$meta, array $data)
     {
         // Username can also be number and stored as such.
-        $key = (string)($data['username'] ?? $entry['key']);
-        $entry['key'] = mb_strtolower($key);
-        $entry['email'] = isset($data['email']) ? mb_strtolower($data['email']) : null;
+        $key = (string)($data['username'] ?? $meta['key']);
+        $meta['key'] = mb_strtolower($key);
+        $meta['email'] = isset($data['email']) ? mb_strtolower($data['email']) : null;
     }
 
     /**
diff --git a/system/src/Grav/Framework/Flex/FlexIndex.php b/system/src/Grav/Framework/Flex/FlexIndex.php
index d792c8506..61526ac97 100644
--- a/system/src/Grav/Framework/Flex/FlexIndex.php
+++ b/system/src/Grav/Framework/Flex/FlexIndex.php
@@ -69,6 +69,15 @@ class FlexIndex extends ObjectIndex implements FlexCollectionInterface, FlexInde
         return $storage->getExistingKeys();
     }
 
+    /**
+     * @param array $meta
+     * @param array $data
+     */
+    public static function updateObjectMeta(array &$meta, array $data)
+    {
+        static::updateIndexData($meta, $data);
+    }
+
     /**
      * Initializes a new FlexIndex.
      *
@@ -676,7 +685,7 @@ class FlexIndex extends ObjectIndex implements FlexCollectionInterface, FlexInde
                     if ($keyField !== 'storage_key' && isset($row[$keyField])) {
                         $entry['key'] = $row[$keyField];
                     }
-                    static::updateIndexData($entry, $row ?? []);
+                    static::updateObjectMeta($entry, $row ?? []);
                     if (isset($row['__ERROR'])) {
                         $entry['__ERROR'] = true;
                         static::onException(new \RuntimeException(sprintf('Object failed to load: %s (%s)', $key,
@@ -712,6 +721,11 @@ class FlexIndex extends ObjectIndex implements FlexCollectionInterface, FlexInde
         return $index;
     }
 
+    /**
+     * @param array $entry
+     * @param array $data
+     * @deprecated 1.7 Use static ::updateObjectMeta() method instead.
+     */
     protected static function updateIndexData(array &$entry, array $data)
     {
     }
diff --git a/system/src/Grav/Framework/Flex/FlexObject.php b/system/src/Grav/Framework/Flex/FlexObject.php
index 39469c929..c97ac9767 100644
--- a/system/src/Grav/Framework/Flex/FlexObject.php
+++ b/system/src/Grav/Framework/Flex/FlexObject.php
@@ -614,6 +614,9 @@ class FlexObject implements FlexObjectInterface, FlexAuthorizeInterface
         $value = reset($result);
         $meta = $value['__META'] ?? null;
         if ($meta) {
+            /** @var FlexIndex $indexClass */
+            $indexClass = $this->getFlexDirectory()->getIndexClass();
+            $indexClass::updateObjectMeta($meta, $value);
             $this->_meta = $meta;
         }